WASHINGTON — On the same day in late November, the Supreme Court came face to face twice with a familiar nemesis: Congress.

In the first of two oral arguments, Justice Samuel Alito, still nursing his morning coffee, denounced as "gibberish" a law Congress passed in 1998 to make federal courts the place to resolve class-action lawsuits involving securities.

For the justices, it was all in a day's work. Much of what they do for a living is clean up after Congress.

"The complexity of the federal legislative process practically guarantees that it will spit out a lot of gibberish," says Jay Wexler, a professor at Boston University School of Law who monitors Supreme Court oral arguments for the type of laughter that often follows denunciations of Congress.

Several factors may be causing an increase in the frustration level between Congress and the courts, experts say. The subject matter of legislation has grown more complex, particularly in areas such as the environment, health care and technology. The partisan divide in Congress has grown deeper, making it harder to agree on pesky details. Rushing legislation through the process, such as last month's tax bill, leads to mistakes.

Of course, some of the court's complaints with its neighbor across the street are more serious. On consecutive days in 2013, for example, it found key sections of the 1968 Voting Rights Act and 1996 Defense of Marriage Act unconstitutional, leading to landmark decisions on racial justice and same-sex marriage.

The same thing may happen this year to a law enacted a quarter century ago to regulate sports betting. From the sound of last month's oral argument, a majority of justices appear ready to declare it unconstitutional and give states more leeway.

In other cases, the justices simply can't tell what Congress meant to say. That leads on rare occasions to a ruling that laws passed and signed by the president are unconstitutionally vague. That was the court's verdict in 2015 for a section of the Armed Career Criminal Act of 1984 that treated as violent felonies crimes in which no violence occurred.

Following the text

Then there are statutes that simply give the justices heartburn, and often they cannot be fixed.

Thus it was last year when Justice Ruth Bader Ginsburg denounced as "stunningly anachronistic" a law that gave children born overseas to unmarried mothers who are U.S. citizens a faster path to citizenship than those whose fathers are the U.S. citizens.

Because children of married U.S. citizens also were given the longer path to citizenship, the only way for the court to make things fair was to deny the exception for children of unwed mothers — making things harder for families, not easier.

Unless the laws are unconstitutional, the court usually tries to match its rulings with Congress' rhetoric, no matter how poorly written. That's particularly true of the conservative justices, who adhere more closely to the text of congressional statutes.

But the late Justice Antonin Scalia, a strict "textualist" and co-author of Reading Law: The Interpretation of Legal Texts, gradually persuaded even his liberal colleagues to give Congress the benefit of the doubt.

"We're all textualists now," Kagan has said out of respect for her departed colleague.

Rigid readings of congressional statutes clash with what Bryan Garner, Scalia's co-author and an authority on legal and legislative writing, calls "legislative free-riding." That's when lawmakers leave it to regulators or courts to figure out the details.

“That is a fairly common phenomenon," says Garner, whose latest book is Guidelines for
Drafting and Editing Legislation. "It’s arguably on the rise, and I think it’s traceable to non-textual means of interpretation.”

The problem leaves justices and judges with three options, he says. They can stick to the written word, try to decipher Congress's purpose, or seek the more desirable outcome — the latter representing the type of judicial activism conservatives despise.

'This means nothing'

In the whistleblower case, Justice Neil Gorsuch, Scalia's successor, said Congress's words restricted protection to those who report wrongdoing to the Securities and Exchange Commission, rather than going through the normal corporate channels.

"How much clearer could Congress have been?" Gorsuch said.

"It's odd. It's peculiar. It's probably not what Congress meant," Kagan said. "But what makes it the kind of thing where we can just say we're going to ignore it?"

Stephen Wermiel, a constitutional law professor at American University's Washington College of Law, said Congress often leaves laws murky because it cannot agree on the specifics.

“Sometimes the problem is deliberate on Congress’s part," Wermiel said. "They either didn’t want to get into the weeds or for political reasons couldn’t agree on where to go.”

Alito thought he had an answer to Kagan's question in the securities class action case. There, Congress in 1998 sought to fix a 1933 law that had left unclear where class action lawsuits involving securities should be heard.

"Our late colleague wrote a book called Reading Law, which provides guidance about how you read statutes," Alito said. "And I looked through that to see what we are supposed to do when Congress writes gibberish."

Neal Katyal, arguing on behalf of Cyan, Inc., a now-defunct company that supplied hardware and software for communications networks, agreed the law was "obtuse" rather than a "model of clarity." He told the justices that they "could have written a much better statute than our friends across the street." But declaring it to be gibberish, he said, was a stretch.

Alito wasn't convinced.

"Is there a certain point at which we say this means nothing?" he said, perhaps wishing he had more coffee. "We can’t figure out what it means, and, therefore, it has no effect?”